Vernier control device



July 21, 1970 R. D. HOUK VERNIER CONTROL DEVICE 2 Sheets-Sheet 1.

Filed July 29, 1968 INVENTOR. RICHARD D. HOUK ATTORNEYS United StatesPatent VERNIER CONTROL DEVICE Richard D. Honk, Stow, Ohio, assignor, bymesne assignments, to North American Rockwell Corporation, Pittsburgh,Pa., a corporation of Delaware Filed July 29, 1968, Ser. No. 748,309Int. Cl. F16c 1/10 US. Cl. 74-502 4 Claims ABSTRACT on THE DISCLOSURE Acontrol device for moving the core of a push-pull control cable axiallywith respect to the casing thereof in gross amounts and, selectively, inaccurately fine, or vernier, increments. The control device has ahousing that is secured to the casing of the control cable. A guidesleeve is pivotally mounted in said housing and slidably receives anoperating rod, one end of which is connected to the core of thepush-pull control cable. The other end of the operating rod presents acontrol knob exteriorly of the housing. A spring means biases thepivotally mounted guide sleeve such that threads on the exterior surfaceof the operating rod are constantly urged toward engagement with matingtooth means presented from the housing. Rotation of said control knob,and thus said operating rod, provides vernier operation; a transverseforce applied to said control knob sufficient to overcome said springmeans and disengage the thread means from said tooth means followed byaxial translation of said operating rod provide gross operation.

BACKGROUND OF THE INVENTION The present invention relates generally tocontrols for push-pull cables. More particularly, the present inventionrelates to a control device for actuating the core of a push-pullcontrol cable with respect to the casing thereof. Specifically, thepresent invention relates to a control device for moving the core of apush-pull control cable with respect to the casing thereof in grossamounts, and, selectively, with accurately fine, or vernier, increments.

Push-pull control cables are generally well known to the art as devicescapable of transmitting mechanical motion in either direction when atleast the ends of the cable casing are satisfactorily clamped inposition. Push-pull cables, being flexible, are particularly suitablefor installations where the cable is required to extend through a numberof bends between a control station and a remote, controlled station.Such cables are constructed to have a core slidably received in asupport casing and are commonly utilized in conjunction with suchdevices as throttle controls. For many such installations it isimperative that the control be capable of providing not only quick,major adjustments in gross but also fine, accurate, Vernier adjustments.i

Heretofore, several known control devices have been employed to providesuch a result. The most widely known construction is quite complex inthat it requires that the tubular support attached to the cable casingslidably receive a tubular adjusting member attached to the cable coreand in which is also slidably received a release rod for positioning aball-like engaging member into and out of mating engagement with thethreaded interior of the tubular support member. A primary control knobis secured to the adjusting member and coaxially receives a secondarycontrol knob secured to the release rod. To make a Vernier adjustmentthe operator need only turn the primary control knob in the appropriatedirection. How ever, for gross adjustment the operator is required toactuate the secondary control knob axially with respect to the 3,521,502Patented July 21, 1970 primary knob and, while maintaining the secondarycontrol knob actuated against the biasing action of the spring means,move the primary control knob axially in the desired direction.

Under even the most favorable conditions considerable manual dexterityis required to operate such a control. In moments of stress the resultscan be disastrous.

In order to alleviate the hazards imposed by the requirement of theaforementioned dextrous manipulation, many substitute constructions havebeen proposed. Exemplary of such proposals is a complex constructionwhich eliminates the secondary control knob. The construction employs acontrol knob nonrotatably and axially slidably mounted on a tubularadjusting member which interacts with a release rod by a plurality ofspring biased, pivotal dogs carried on the tubular adjusting member andengageable between the knob and release rod. For gross control theoperator must always apply sutficient pressure to overcome the springbias and thereafter move the control knob in the desired direction.Accordingly, approximation of incremental adjustments in gross are mostdifiicult, if not impossible, to obtain.

Similarly, another construction utilizes an annularly interrupted springsleeve embracing a frame sleeve in which an operating rod is slidablyreceived. The spring sleeve biases a ball into engagement with thethread means on the exterior of the opearting rod. Here too, in grosscontrol can be eifected only after sufficient force is applied to thecontrol knob to overcome the preloading resistance offered by the springmeans to maintain the ball in engagement with the thread means.

In the afore-described configuration the operating rod Was, and couldbe, moved only axially. This factor itself engendered the necessity forcomplicated mechanisms to effect selection of in gross or Vernieroperation.

There is one prior known construction that obviated the necessity forcomplex mechanisms to promote selected Vernier or in gross operation byeliminating the restriction that the operating rod move only axially. Inthat control the operating rod was mounted so that it could be firstswung to select the type of operation desired and thereafter removedaxially to effect the in gross or Vernier operation selected. This priorart construction connects the operating rod pivotally to the end of thecore. The rod itself is threaded and swingable into and out ofengagement with a half nut. When the rod is in engagement with the halfnut, Vernier operation is accomplished by rotation of the control rod.When the rod is out of engagement with the half nut, gross operation iseffected merely by translation of the control rod.

With such a control, however, the angle through which the operating rodmust swing to change from vernier to gross operation varies directlywith the particular setting. That is, when the pivotal connectionbetween the operating rod and the cable core is remote from the halfnut, the operating rod needs swing through only a modest angle toengage, or disengage, the half nut. This angle increases markedly as thepivotal connection between the rod and the cable core approaches thehalf nut.

The inherent disadvantages in such a control are readily appreciated.During in gross operation the angle must be constantly varied to assurethat the control does not catch. Moreover, as the pivotal connectionbetween the cable core and the operating rod approaches the half nut,the distance through which the knob, or handle, on the end of the rodmust move to maintain gross control is compounded by the constantlyincreasing angularity. This exaggerated distance is a constant hindranceto facile operation, and this prior art control has not, therefore, metwith favorable reception.

3 SUMMARY OF THE INVENTION It is therefore a primary object of thepresent invention to provide, for the core of a push-pull control cable,a control device in which gross or vernier operation may be selected byswinging the operating rod through a fixed angle irrespective of theprevious control setting.

It is another object of the present invention to provide a controldevice, as above, which employs only a single control knob.

It is a further object of the present invention to provide a controldevice, as above, that may be converted from vernier to gross operationmerely by applying a modest transverse force to the control knob, ingross operation being thereafter effected by axial translation of thecontrol knob with a return to vernier control occasioned merely byreleasing the application of transverse force to the control knob.

It is a still further object of the present invention to! provide acontrol device, as above, that is relatively uncomplex and economical tomanufacture and maintain.

These and other objects which will become apparent from the followingspecification are accomplished by means hereinafter described andclaimed.

In general, a control device according to the concept of the presentinvention has a housing adapted to be connected to the casing of apush-pull control cable. A guide sleeve is mounted in the housing forpivotal movement about a fulcrum located substantially adjacent theconnection of the control cable casing to the housing. An operating rodis slidably received Within the guide sleeve, and one end of theoperating rod is connected to the core of a push-pull control cable. Theother end of the operating rod is secured to a control knob locatedexteriorly of the housing.

A tooth means is presented from the housing for selective engagementwith thread means on the exterior of the operating rod, the tooth meansbeing preferably remote from the fulcrum about which the guide sleevepivots. A spring means operatively connected between the housing and theguide sleeve biases the guide sleeve about its fulcrum so as to urge thethread means on the operating rod into engagement with the tooth meanspresented from the housing.

Vernier operation is effected by rotation of the control knob. Grossoperation is selected merely by applying a transverse force to thecontrol knob sufficient to overcome the spring means and therebydisengage the thread means on the operating rod from the tooth meanspresented from the housing. With gross operation thus selected it iseffected by axial translation on the control knob.

One preferred embodiment is shown by way of example in the accompanyingdrawings and described in detail without attempting to show all of thevarious forms and modifications in which the invention might beembodied; the invention being measured by the appended claims and not bythe details of the specification.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, partly brokenaway and partly in section, depicting a pushull control cableoperatively connected to a control device embodying the concept of thepresent invention with the mechanism positioned to provide verniercontrol;

FIG. 2 is a top plan view of the control device depicted in FIG. 1;

FIG. 3 is an enlarged cross section taken substantially on line 33 ofFIG. 1;

FIG. 4 is an enlarged cross section taken substantially on line 4-4 ofFIG. 1;

FIG. 5 is an enlarged cross section taken substantially on line 55 ofFIG. 1 depicting the relationship of the mechanism during vernieroperation in solid line representation and the relationship of themechanism during gross operation in chain line representation; and

4 FIG. 6 is a view similar to FIG. 1 depicting the mechanism positionedto provide gross control.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawings, the improved control embodying the concept of the presentinvention is indicated generally by the numeral 10 and is depicted asbeing operatively connected to a push-pull control cable 11. Thepush-pull control cable 11 includes a core 12 and casing 13 in which thecore 12 is reciprocally slidable.

The prior art knows many casing constructions, one of which is depictedenvironmentally herein and comprises a plurality of wires 14contiguously laid in the form of a helical coil about the radially outersurface of an inner, flexible tube 15 that extends the full length ofthe casing 13. An outer flexible cover 16 encases coil of wires 14 andextends along the entire casing to within a short distance from the endsof the wires 14.

A fitting 18 is received over the end of the coil of wires 14 and cover16 and is securely attached thereto, as by swaging. The fitting 18, andthereby the casing 13, is connected to the housing 19 of control 10. Thehousing 19 may be secured to an instrument panel 20 as by bolts 21 thatextend through both the panel 20 and mounting tabs 22 extendinglaterally from the housing 19.

The housing 19 is of generally inverted U-shaped cross section with two,opposed, spaced, side walls 23 and 24 extending downwardly from the webor base, wall 25. To secure the cable casing 13 within housing 19 ananchor bushing 26 may be employed. The anchor bushing 26 is closelyfitted within the housing 19 with an aligning nub 28 extending outwardlytherefrom matingly received within a bore 29 in the web wall of thehousing 19.

The anchor bushing 26 is bifurcated with a pair of spaced legs 30 and 31extending outwardly from the body portion 32 to define an arch 33therebetween. The arch 33 engagingly receives a portion of the outersurface of the end fitting 18. A rib 34 extends from the arch 33 alongat least a portion of the opposed legs 30 and 31 to mate with a portionof a corresponding annular recess 35 in the outer surface of the endfitting 13. A lock rivet 36 extends between the legs 30 and 31 and isreceived within the recess 35 in fitting 18 on the side thereof opposite to arch 33. With the fitting 18 so received, the cable casing 13is anchored against axial displacement with respect to the control 10.

Also mounted within the housing 19 is a guide sleeve 40. The guidesleeve 40, which may be made in opposed, longitudinal sections 40a and40b suitably riveted together as at 38 and 39, is mounted Within thehousing 19 to pivot about a fulcrum located in preferably closeproximity to the end fitting 18. As shown, a pin 41 adjacent the anchorbushing 26 may comprise the fulcrum. The fulcrum pin 41 extends betweenthe opposed side walls 23 and 24 of the housing 19 and is rotatablyreceived Within a bore 42 through a mounting ear 43 on one end of theguide sleeve 40.

The guide sleeve 40 is also axially bored, as at 44, slidably to receivean operating rod 45. One end of the rod 45 extends axially outwardly ofthe sleeve 40, and housing 19, to mount a control knob 46. The oppositeend of the rod 45, within sleeve 40, is attached to the core 12 of thepush-pull control cable 11.

Inasmuch as the operating rod 45 will rotate with respect to the housing19 during vernier adjustment, as is more fully hereinafter described,and because the cable core 12 is often attached at the remote controlledstation in such a Way that rotation thereof would be undesirable, it ispreferable that the operating rod 45 be rotatably attached to the core12. Exemplary of a construction that provides such a result, acylindrical plug 4-8 may be swaged or otherwise afiixed to the core 12.The plug 48 is rotatably received within an axial bore 49 in rod 45. A

retaining washer 50 is positioned within the bore 49, in the axiallyouter end of plug 48, and may be retained therein by upsetting, ordimpling, the end of rod 45, as at 51.

Near the end of sleeve 40 opposite mounting ear 43 is a gate 52. Thegate 52 comprises an aperture through the sleeve 40 to expose at least aportion of the operating rod 45. A tooth block 53 is secured to thehousing 19 such that the teeth 54 thereof will extend through the gate52 and intermesh with conforming threads 55 on the radially outersurface of the operating rod 45. The tooth block 53 is closely fittedwithin the housing with an aligning nub 56 extending outwardly therefrommatingly received within a bore 58 in the web wall 25 of the housing 19.A pin 59, that extends through registered bores 60 and 61 in the opposedside Walls 23 and 24, respectively, of the housing 19, is press fitwithin a bore 62 through tooth block 53 to retain the latter fixedlywithin the housing 11.

The ends of the pin 59 extend transversely beyond the side walls 23 and2-4 to present pommels 63 and 64 behind which the end loops 65 and 66 ofcoil tension springs 68 and 69, respectively, can fasten. A similar pin70 is press fit transversely through the sleeve 40 in spaced oppositionto pin 59 and is similarly pomrneled, at 71 and 72, to retain theopposed end loops 73 and 74 of springs 68 and 69.

Suitable arcuate slots 75 and 76 are provided in the side walls 23 and24 of housing 19 to permit the guide sleeve 40 to pivot about fulcrumpin 41 without interfering contact between the pin 70 and the housing19.

Although a variety of designs for the teeth 54 on block 53 and thethreads 55 on operating rod 45 may be utilized, the acme threadsdepicted work very well for this control.

With the teeth 54 intermeshed with the threads 55 critical axialtranslation of core 12 can be effected by rotation of knob 46. Shouldgross translation of the core be desired, or required, one merelyapplies a suflicient transverse force against knob 46 to overcome thebiasing action of springs 68 and 69 and disengage the threads 55 on rod45 from the teeth 54 on block 53. With the teeth and threads thusunmeshed the rod 45 may be translated axially in gross.

To convert from gross to vernier operation one releases the transverseforce applied against the knob 46 and the biasing action of springs 68and 69 swings the guide sleeve 40 so as to move the threads 55 on rod 45toward the teeth 54 on "block 53. If acme threads 55 are utilized, theymay not make instant meshing contact with teeth 54, but with the biasingaction imparted by springs 68 and 69 as soon as the rod 45 is eitherpartially rotated or moved axially the threads 55 will be swung intomeshing engagement with the teeth 54 so that rotation of knob 46 effectsvernier operation.

It should now be apparent that irrespective of the axial position of thecontrol knob 46 disengagement of the threads 55 on rod 45 from the teeth54 on block 53 will be accomplished by rotation of guide sleeve 40through a fixed angle 80.

For example, to allow a 3" axial travel for the operating rod 45, andthereby core 12, a span of approximately three and one-half inches isrequired between the pivot pin 41 and the teeth 54 on block 53. Using aouter diameter operating rod with acme threads having a depth ofapproximately 0.05 6 inch an assured clearance between the threads 55and teeth 54 is provided if the threads 55 are translated at least 0.075inch away from tooth block 53 against the biasing action of springs 68and 69i.e., the rod 45 will be swung through an angle of approximately 114 about pivot pin 41 to disengage the threads 55 from teeth 54. And,this angle Will remain constant throughout the 3" axial travel providedfor rod 45.

However, should the operating rod be pivoted onto thecore, as is done inthe prior art construction discussed earlier, the angle through whichthe rod must be swung to disengage the teeth will increase markedly asthe operating rod approaches the outer extent of its travel. Forexample, should an identical operating rod with acme teeth be pivotedonto the core, the same clearance provided above would require avariation in angular displacement from approximately 114 at theinnermost extent of its travel to approximately 8 32 at the outer extentof the 3" travel.

To thus compound the distance through which the knob 46 must, travel tochange from vernier to gross control greatly decreases the facility withwhich the control is operated. A control embodying the concept of thepresent invention thus provides a fixed angular displacement throughwhich the operating rod must be swung to change from vernier to grossoperation and otherwise accomplishes the objects of the invention.

What is claimed is:

1. A vernier control device for a push-pull control cable, said controlcable having a core and easing, said control device comprising a housingsecured to said control cable casing, a guide sleeve pivotally mountedin said housing, an operating rod slidably received in said guidesleeve, said operating rod operatively secured to said cable core,thread means on said operating rod, tooth means presented from saidhousing, spring means biasing the teeth on said operating rod intoengagement with the teeth presented from said housing.

2. A vernier control device, as set forth in claim 1, in which the guidesleeve is pivoted on a fulcrum, said fulcrum being located substantiallyadjacent the connection of said cable casing to said housing and remotefrom the teeth means presented by said housing for engagement with thethread means on said operating rod.

3. A vernier control device, as set forth in claim 2, in which thespring means is connected between said housing and said guide sleeve.

4. A vernier control device, as set forth in claim 3, in which a gate isprovided in said guide sleeve and the tooth means engages said threadmeans through said gate.

References Cited UNITED STATES PATENTS 2,101,160 12/1937 Weber 745022,132,919 10/1938 Arens 74502 2,386,767 10/1945 Arens 74-502 2,848,9028/1958 Hale 74502 WESLEY S. RATLIFF, JR., Primary Examiner 3 3 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 521 502 D td July 21 1970 Inventor(s) RICHARD D. HOUR It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 5, line 1, after "in" insert engagement with Sibfifii Aim SEALEDmv 1 mm M Hadron]- n 2 mm L m I- 1 Offioer Y Oomiaaiom of MI

